[Resolved] doesn't work with social plugin

I want my site members to login/register with social login (twitter/facebook) and upon login/register I want to force them to fill mandatory buddypress profile fields.
When I enable ‘Social Login’ (http://wordpress.org/extend/plugins/oa-social-login/) and BP Force Plugin, I am getting error.

Warning: Cannot modify header information – headers already sent by (output started at /home/XXXX/public_html/YYYY/wp-content/plugins/buddypress/bp-themes/bp-default/header.php:3) in /home/XXXX/public_html/YYYY/wp-includes/pluggable.php on line 876

The Error: Warning: Cannot modify header information – headers already sent by (output started at /mnt/web/htdocs/page/wp-content/plugins/buddypress/bp-themes/bp-default/header.php:3) in /mnt/web/htdocs/page/wp-includes/pluggable.php on line 876

Please fix it, because the plugin could be very, very useful for BP-Admins 🙂